Sterilizer



J. SCOTT STERILIZER Oct. 5, 1937.

Filed March 27, 1935 Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to sterilizers, and more particularly to apparatus designed to sterilize dental instruments, and is fully illustrated in the accompanying drawing, in which,-

Fig. 1 is a perspective View of the apparatus; Fig. 2 is a view, partly in section, showing an instrument in the sterilizer; Fig. 3 is a sectional view along the line 3-3 of Fig. 2; and Fig. 4 is a detailed sectional view along the line 44 of Fig. 2.

Proper sterilization of dental instruments is preferably accomplished through the use of boiling water. It is necessary that the portion of the instrument which is to come in contact with the patient be exposed either to hot water or steam for a reasonable length of time before its use in order to insure its sterile condition.

Dental and medical sterilizers now in use comprise closed containers having therein one or more perforated shelves upon which the instruments may be laid. Provision is also made for placing water in the container and for heating it to the boiling point. The shelves are sometimes situated below the water level, in which case the instruments are actually submerged in the boiling water, and sometimes above the surface of the water, in which case the instruments are exposed to live steam. The containers are completely closed when in use, so that the water vapor condenses and returns to the water, rather than passing off into the atmosphere.

These sterilizers have been found to have several defects. The continual vaporization and condensation of the water results in the formation of a scum in the sterilizer, which tends to deposit on the instruments when they are lifted from the sterilizer. The instruments are, moreover, heated equally throughout, and since the handles are generally much heavier than the tool end, they therefore cool off much more slowly and thus necessitate a considerable period of delay before the instruments may be comfortably handled.

The sterilizers, comprising closed containers effecting sterilization of the entire instrument, were designed for the needs of the medical profession. When an operation is being performed, for example, the surgeons hands are carefully sterilized, he wears sterile gown and gloves, and the tables, the fioor of the operating room, etc., are all washed with an antiseptic solution. In this environment an unsterilized instrument handle would be a possible source of infection not to be permitted, and the entire instrument must, therefore, be sterilized. The sterilizers used by the dental profession have, up to the present invention, always been of the same type as those used for surgical instruments. Sterilization of the handles of dental instruments, however, is not only unnecessary but futile, since a 5 dentist does not sterilize his hands, nor does he keep the rack or tray, on which he lays his instruments between operations, in a sterile condition.

This invention obviates many defects of the sterilizers now in use by providing a bowl, open to the atmosphere, containing boiling water into which the ends of the instruments are submerged, and by providing a rack above the bowl for supporting the handles of the instruments. The only portion of the instruments contacting the patient are thus thoroughly sterilized, while the handle is'not heated objectionably, and an in strument may be thus lifted from the sterilizer at any time it is desired. Since the tool end of the instrument is generally quite thin, it cools rapidly upon exposure to the air and the instrument may be used almost immediately after removing it from the sterilizer. The fact that all of the instruments have their handles within reach of the user, moreover, is an advantage in that it does not require that a lid be removed and trays or shelves lifted out in order to remove an instrument from the sterilizer for use.

In the particular embodiment of this invention illustrated herewith, a base I 0 is provided with an opening II and shoulder portions I2 adapted to receive a bowl I 3. The bowl I 3 has opening into it a channel portion 14, which extends to a point beneath the opening l5 of an inverted container l6, as a bottle. The neck ll of the bottle or container I6 is received by a recess or en larged portion I8 in the end of the channel l4, while the container is supported in the desired position by a clamping member 19, which memher is mounted on a standard 20. The standard 20 is mounted on the base In adjacent the bowl l3 by any convenient means, as by the bolt 2|. The standard 20 also acts as a support for the rack 22, which rack is adapted to support instruments having their ends in the bowl, as the handle 23 of the dental instrument 24 having a tool end 25.-

The bowl I3 is filled with a liquid, as the water 26, to a desired surface level, as the illustrated position of the surface 21. The fact that the neck of the inverted bottle or container 16 has its opening at this level insures the maintenance of the desired level of the surface 21 as long as liquid remains in the container or reservoir I 6,

despite any loss of liquid from the bowl due to vaporization into the atmosphere.

The bowl i3 is provided, in the bottom thereof, with a heating means adapted to maintain the Water at or substantially near boiling temperature. The heating means is here shown as an electric resistance element 35 in the water, which element is supported by insulating material 28 supported in the bottom of the bowl. Two leads or wires 29 and 30 are provided to supply the current, and a pair of contact points3l and 32 are provided in series with one of these leads. Thermally operated means serve to separate these contact points and break the circuit if the element 35 becomes overheated for any cause, as for example when the bowl runs dry.

It is readily apparent that the sterilizing unit described herein is simple, convenient, and efiicient. The liquid level is maintained at the proper position until the container or bottle is empty, whereupon the bottle or reservoir 3 should be removed, refilled, and replaced in the operative position shown in the drawing. Should this be neglected for any reason, however, the thermally operated safety switch means renders the unit safe should the bowl be permitted to run dry. The rack is adapted to hold a number of instruments simultaneously, and yet enables the instruments to be removed one by one when it is desired to use them. The convenience and accessibility of the sterilizer encourage constant sterilization of the instruments, since the user may lay them back in the sterilizer between operations, rather than laying them on an unsterile tray or shelf.

While I have shown and described certain em.- bodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as possible in view of the prior art.

What I regard as new, and desire to secure by Letters Patent, is:

1. A sterilizer for sterilizing the tool end of a dental instrument between operations on the same patient, including: a bowl adapted to contain a body of Water having its surface exposed to the atmosphere; means for maintaining the surface of said water at a desired level in said bowl; means for maintaining said Water substantially at its boiling temperature; and a rack substantially removed from the surface of said water, whereby an instrument is supported with its tool end in said water and its handle sufficiently removed therefrom to enable the instrument to be easily placed in and removed from said sterilizer during operation thereof at frequent intervals.

2. A sterilizer for sterilizing the tool end of a dental instrument between operations on the same patient, including: a bowl adapted to contain a body of water having its surface exposed to the atmosphere; an inverted container for water; an open channel connecting said container and said bowl, whereby the surface of said water is maintained at a desired level in said bowl; means for vmaintaining said water substantially at its boiling temperature; and means for supporting said instrument with its handle out of the water and its tool end submerged therein, whereby it, may be easily placed in and removed from said sterilizer at frequent intervals.

3. A sterilizer for sterilizing the tool end of a dental instrument between operations on the same patient, including: a bowl adapted to. contain a body of water having its surface exposed to the atmosphere; an inverted container for Water; an open channel connecting said container and said bowl, whereby the surface of said water is maintained at a desired level in said bowl; means for maintaining said water substantially at its boiling temperature; and a rack substantially removed from the surface of said water, whereby an instrument is supported with its tool end in said water and its handle sufficiently removed therefrom to enable the instrument to be easily placed in and removed from said sterilizer during operation thereof at frequent intervals.

JAMES SCOTT. 

